Snap switch



May 16, 1944. -F Y E 2,348,982

SNAP swncn Filed. Feb. 6, 1943 2 sheets-sheet, 1

8 IO 80 I9 F|6.4

I20 I70 I30 I60 INVENTOR. FRANCIS W. JOYCE -14 I BY 7/ y 16, 1944- F. w. JOYCE 7 2,348,982

SNAP SWITCH Filed Feb. 6, 1943 2 Sheets-Sheet 2 INVENTOR. FRANCIS W. JOYCE "flfififlww "AUQBNEY Patented May 16, 1944 SNAP SWITCH Francis W. Joyce, Chicago, 111.. assignor to Gleason Sales 00., Chicago, 111., a corporation of Illinois Application February 6, 1943, Serial No. 474,952

2 Claims.

My invention relates in general to an improved ,snap acting switch, and more specifically to an improved electrical switch having a movable contact which moves from one position to another by a snap action as a result of a very small movement of its operating member.

Among the objects of my invention are to provide a switch of the above type in which the parts are simple of construction and operation and in which a very light pressure is required upon the operating element to cause operation of the switch.

Another object is the provision of such a switch whose parts are easily mounted and require only slight adjustment to adapt it to various uses.

Slight changes may be made in the construction of the various parts or in the materials specified for said parts without in any way de:

parting from the spirit of the invention..

Other features and objects will be apparent from a. reading of the following detailed description:

Fig. 1 is a top view of my improved snap switch with the cover cut away.

Fig. 2 is a side view taken from the upper side of the device with the side of the cover cut away.

Fig.3 is another side view taken from the bottomof Fig. 1 with the side of the cover cut away.

Fig. 4 is an end view taken from the right of Fig. 3 with the end of the cover cut away.

Fig. 5 is an end view taken from the right of Fig. 2 with the end of the cover cut away.

Fig. 6 is a bottom view of the device of Fig. 1.

Figs. '1, 8, 9, 10 and 11 are detail views of the springs and other operating parts.

Figs. 12, 13 and 14 are diagrammatic views showing the switch in normal, part operated and operated positions, respectively.

Referring now to Figs. 1, 2 and 3 the snap switch comprises a base 2 and a cover In of Bakelite Or other insulating material, the base being formed as shown to provide proper mounting holes and indentations for supporting the metal elements of the switch. The main spring or contact making element of the switch is the spring 3 (shown in detail in Fig. '7) formed as shown of beryllium copper or any other suitable conducting material. It has a double faced fine silver contact surface 4 at its central point. This point may of course be of any other suitable alloy or metal. The base of spring 3 has the three mounting holes as shown and the long horizontal arm thereof, containing the contact points 4 at its central portion, is formed perfectly flat and straight. The operating member 5 (Fig. 8) has a part 5a formed as shown of brass or the like having the groove 6 in its outer downturned free end and is riveted at its other end to a U-shaped part 51) formed preferably of beryllium copper or the like. The base of the U-shaped part 51) has mounting holes registering with those in the base of spring 3. A third element consists of the rigid brass mounting plate 1 formed with a base and the upturned end as shown in Fig. 9 and also having mounting holes in its base registering with those in the base portions of spring 3 and operating member 51). Referring now to Figs. 2 and 3 these three elements are mounted as shown with the base of spring 3 against the insulating base 2. The base of operating element 5b is mounted above the base of spring 3 with the element 1 on top of both. A pair of rivets 8 and 8a extend through the-two outer holes of the three parts and through the base 2 and a conducting plate 3 on the lower side of base 2 (Fig.

6). The center hole in part 1.is threaded and a conducting screw in extends through the plate 9 and through the center holes of spring 3 and element 5 into the threaded hole to form thecircult connection by which any wire may be attached and thereby electrically connected to spring 3 and element 5.

From Figs. 12-14 it will be seen that the outer free end of spring 3 is flexed and inserted into the groove 8 in the free end of operating element,

5. This can be accomplished by flexing part 51) of part 5 to move the free end containing groove 6 outward to the left until spring 3 can be snapped in place in the groove. The tension of part 5b now exerts a longitudinal pressure on spring 3 which causes the spring 3 to have a tendency to bow upward as shown in the diagrammatic view in Fig. 12. The upward bowing of spring 3 would be greater except that part 5a is held from further upward movement by plunger l9. When thus assembled it will be seen that the upwardly extending arm of part 1 acts as a stop against which the upwardly extending part 3a of spring 3 is pressed by the longitudinal compression of' spring 3. In Fig. 1.0 I have shown the brass contact element H which is riveted (Figs. 2, 3 and 4) at I! to the base 2 and to a brass conducting plate |2a (Fig. 6) on the under side of base 2. At i3 is a threaded hole which receives the terminal conducting screw l3a which passes through a hole in plate 12a. At It on the under side of plate H is deposited a large contact surface of fine silver or similar rare metal which acts as an upper contact surface above the contact point 4 on spring 3 (Fig. 2) The lower contact point is supplied by a similar conducting plate II! of brass or the like which is formed as shown in Fig. 11.

I6 secures the plate securely to base 2 and a conducting plate lGa on the lower side of base 2. A screw hole I! receives the terminal screw l'la which passes through a hole in plate l6a and base 2. At I8 is deposited or welded a contact surface l8 which again is of fine silver. or like conducting metal or alloy.

Referring now to Figs. 12, 13 and 141 have shown the different operating elements in normal, semi-operated and fully operated positions somewhat exaggerated to illustrate the operation. Fig. 12 shows how the tension of spring part b tends to bow the spring 3 in an upward direction normally so that part 5a .is pressing normally against an operating plunger l9 which extends through a hole in the cover 2a. Any desired means such as a magnet armature or other operating element may press against the outward extending stem of plunger H to press the plunger down into the case. As plunger [3 moves down it presses member 5a down to the position shown in Fig. 13 against the tension of spring link 5b to gradually straighten out the bow in spring 3. Downward movement of part 5 stores further tension in spring 5b. Up to this time the contact 4 continues to press against the lower contact l3. As soon as part 5a moves down past the dead center line of spring 3 then the compression of said spring causes it to snap over and form a bow in the opposite direction as shown in Fig. 14 and snap the contact 4 out of engagement with contact l8 and into engagement with upper contact H. A stop 20 formed in base 2 limits the downward movement of the end of element 5a. As soon as pressure on plunger I9 is released, then the tension, which has been stored in spring element 5b by the downward movement of part 5, exerts itself to overcome the slight downward bow of spring 3 and moves part 5 upward to its normal position again. As part 5 moves upward and spring 3 reaches its center point as shown in Fig. 13 then the resistance to the tension of part 5b is materially lessened and spring 3 reverses its bow and snaps into its normal position as shown in Fig. 12 and its contact is rapidly snapped back against contact I 8.

It will be seen that the amount of longitudinal compression of'spring 3 can be varied by bending the outer end of part 5a, which extends downward and contains the groove 8, to the left or right as seen in Fig. 10, and this will also lessen or increase the tension on spring-5b and consequently vary the amount of pressure required to move the plunger I 3 from normal to operated position. Also it will be seen that the amount of pressure required to operate the switch can be varied by changing the thickness of spring 3, or spring member 5b. The holes 2| and 22 through. the base 2 are clearance holes for A rivet at mounting screws to mount the whole device as desired.

It will thus be seen that the switch has few and simply constructed parts and that only a slight movement of plunger I 3 is required to cause the outer end of part 5a to move past the point where spring 3 passes its horizontal center line and snaps over into a bow in the opposite direction to cause the snapping of contact from one contact to another. Also it will be seen that only one of the contact surfaces I4 and 18 may be used if desired so that only a make or only a break contact is operated instead of the make and break as shown.

Having fully described the features and aspects of my invention, what I consider to be new and novel and desire to have protected, is set forth in the appended claims.

What is claimed is:

1. In a snap switch, a thin leaf spring secured at one end by a mounting member and having an extending arm with a contact point intermediate its ends, a rigid metal arm extending parallel to said spring arm, a flexible spring secured at one end to the metal arm and se cured at the other end to said mounting member at the same point as the spring arm, said flexible spring extending vertically from said point to provide endwise movement for said arm, a hook on the free end of said metal arm, the free end of said leaf spring forced into engagement with said hook, said flexible spring causing endwise tension in said arm and consequent longitudinal compression of said leaf spring and consequent bowing thereof, a movable plunger engaging said metal arm adjacent the end secured to said flexible spring, and electrical contacts above and below the contact point on said leaf spring and engaged alternately by said point as the metal arm is moved up and down.

2. In a snap switch, a thin leaf operating spring having a flat mounting section, a vertical section extending upward from said mounting section and a horizontal section extending outward from said vertical section and containing a contact point near its mid point, a back stop for permitting flexing of the vertical section in only one direction, a rigid metal piece extending substantially parallel to the horizontal section a consequent bow thereof, means for moving the metal piece to'cause a reverse bow to occur in said operating spring and contacts above and below said contact point engaged and disengaged by a snap action of the operating spring.

FRANCIS W. JOYCE. 

